KVNKVN

Single-dish Test Observations of the KVN Yonsei Single-dish Test Observations of the KVN Yonsei telescope at 22/43 GHz - telescope at 22/43 GHz - Performance of KVN Yonsei Performance of KVN Yonsei telescope at 22/43GHztelescope at 22/43GHz

Sang-Sung LeeSang-Sung LeeMarch 18, 2009March 18, 2009

2009 East Asia VLBI Workshop2009 East Asia VLBI Workshop

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Collaboration

Do-Young Byun – Do-Young Byun – Field System managementField System management Do-Heung Je – Do-Heung Je – Receiver System managementReceiver System management Seog-Tae Han – Seog-Tae Han – Quasi Optics managementQuasi Optics management Tomoharu Kurayama – Tomoharu Kurayama – DAS managementDAS management Se-Jin Oh – Se-Jin Oh – DAS and Clock System managementDAS and Clock System management Kee-Tae Kim, Bong Won Sohn – Kee-Tae Kim, Bong Won Sohn – Observation planObservation plan AdvisorsAdvisors: Hyunsoo Chung, Se-Hyung Cho, Duk-Gyoo Roh, : Hyunsoo Chung, Se-Hyung Cho, Duk-Gyoo Roh,

Chang Hoon Lee, Bong Gyu KimChang Hoon Lee, Bong Gyu Kim

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Outline

Introduction Test observations of KVN Goals of single-dish test observations

Observations and results System setup First light and Simultaneous observations Pointing model at 22GHz Beam alignment measurements Aperture Efficiencies

DiscussionOutlook

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Introduction

Test observations of KVN in 2007-2009 100-GHz Acceptance observations (K. T. Kim’s talk) Single-dish test observations at 22/43GHz (This talk) VLBI test observations btw KVN-VERA (B. W. Sohn’s talk)

Goals of single-dish test observations Performance test of KVN telescopes at 22, 43, 86 and 129GHz

• Pointing model

• Aperture efficiencies

Feasibility test of multi-frequency simultaneous observations• Beam alignment measurements (S. T. Han’s talk)

• Instrumental phase stability measurements (D. H. Je’s poster)

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Receiver Cabin

System setup

Observation Building

43 GHz FE

22 GHz FE

Down Converte

r

Down Converte

r

Receiver system DAS Clock Field system

GUI

Control PC

1 pps Distributor

100 MHz Distributor

10 MHz Distributor

10 MHz Distributor

1 pps Distributor

5 MHz

10 MHz

100 MHz

1 pps

1.4 GHz

ClockSystem

H-maser

GPS

Digital O/E

WDMOptical

MUX

DigitalE/O

Sampler

SamplerWDM

OpticalDMUX

DigitalSpectro-meter

Mark5B

DIR-1000

DigitalFiltersDown

Converter

Down Converte

r

Sampler

Sampler

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First lights of KVN Yonsei telescope

First light from H2O masers in W49N at 22GHz22GHzon Aug. 30 2008

Digital spectrometer with wideband mode BW = 512MHz

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First lights of KVN Yonsei telescope

First light from SiO masers in Orion KL at 43GHz43GHzon Aug. 31 2008

Digital spectrometer with narrow band mode 1BW = 256MHz

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Simultaneous observations at 22/43 GHzof KVN Yonsei telescope

Simultaneous observations at 22/43GHz for thermal emission (Venus) on Oct. 6 2008

Two power-streams at 22 and 43 GHz while OTF scanning Venus

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Simultaneous observations at 22/43 GHzof KVN Yonsei telescope

Simultaneous observations at 22/43GHz for maser emission (Orion KL) on Oct. 8 2008

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Pointing model at 22 GHz

Six maser sources : W49N, OrionKL, VY CMa, WB755, W3OH, Cep AObservations on Sep. 10-17 2008RMS error of the pointing model : 4” in AZ, 5” in EL

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22/43GHz beam alignment measurements

Goals: 7" of beam offsets btw 22/43GHz 10% of FWHM (70") at 129GHz

Beam alignment measurements @ K/Q bands Beam offset from 1st measurement (JupiterJupiter):

• ((∆∆AZ, AZ, ΔΔEL)=(1.6EL)=(1.6"", 22, 22")") @ 30° in EL

• No dependency on EL (found by observing Orion KLOrion KL with FIVE Points)

• Adjusting Rx-direction by 2 degrees on the Rx plate

Beam offset from 2nd measurement (JupiterJupiter): • (ΔAZ, ΔEL)=(1.6(ΔAZ, ΔEL)=(1.6"", -2.9, -2.9")") @ 30° in EL

• Within pointing accuracy of 5" and our goal of 7 "

Beam offsets from 3rd measurement (Orion KLOrion KL): • at various ELs of 14 ° ~ 47 °

• with the optimized sub-reflector model

• (<ΔAZ>, <ΔEL>)=(4.2(<ΔAZ>, <ΔEL>)=(4.2"", -0.6, -0.6")")

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Beam offsets from 3rd measurement (Orion KL):

• H2O masers (at 22 GHz) and SiO maser (at 43GHz)

• at various ELs of 14 ° ~ 47 ° and various AZs of 90 ° ~ 210 °

• with the optimized sub-reflector model

• (<ΔAZ>, <ΔEL>)=(4.2", -0.6")

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Aperture efficiencies

Frequencies

Planets

Aperture eff. (%)

EL(°)

HPBW

(“)

TB

(K)

22GHz Jupiter 64 30 LPF2 140 134+-4*

Venus 68 30 LPF2 140 505+-25**

43GHz Jupiter 64.4 30 LPF2 70 150***

Venus 68.8 32 LPF2 70 450+-32***

* : Page et al. 2003 ApJS 148, 39** : Butler et al. 2001 Icarus 154, 226*** : Greve et al. 1994 A&A 286, 654Sub-reflector was optimized in position.Aperture efficiencies are values of single measurements.

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Discussion and Outlook

Discussion Why is the beam offsets btw K/Q dependant in AZ of

observations?• Position difference of H2O and SiO masers in Orion KL?

– (05 35 14.1 -05 22 37.5) , (05 35 14.5 -05 22 30.5)

• System deformation in AZ but not in EL?

• Uncertainty of position of Orion KL?

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Discussion and Outlook

Outlook Receivers at 22/43GHz taken down after the observations. 100-GHz acceptance tests done for KVN YS. Receivers at 22/43GHz set up again on Feb. 2009

need to confirm the results from the previous observations Beam alignment test for planet revisited (S. T. Han’s talk) Beam alignment test for Orion KL to be revisited Double check of pointing model to be done

Polarization characteristic should be measured Gain curve measurements After confirming all the characteristics, we will start single-dish

observations of KVN Yonsei.